Staff at RAF Lakenheath and RAF Mildenhall are in the midst of sweeping reforms by the US Air Force, with sources close to the bases suggesting thousands could leave and not be replaced.

The force last year announced measures to reduce its total staff by 25,000 over five years as part of its ‘sequestration’ programme, adapting to budget cuts totalling billions of dollars.

Technical Sergeant Zachary Melin from RAF Lakenheath confirmed that 1,600 airmen and women from the base were eligible for the first tranche of voluntary redundancy and early retirement programmes, with the total numbers to leave depending on the uptake elsewhere.

He added: “We don’t know how many airmen will ultimately leave Lakenheath in the next year as this is an ongoing process based on overall Air Force numbers, not local quotas.

“The Air Force must implement programmes that reduce the size of our force now in order to meet changing global missions, national security concerns and ongoing budget uncertainty.

“The goal of these Air Force-wide programmes is to reduce the size of our force, while positioning it to meet both current and future mission requirements.”

A statement from RAF Mildenhall also said they did not have to fulfil a specific quota, but confirmed that departures would happen before the end of 2014.

A spokeswoman also confirmed that eligible staff and their families had been offered the same voluntary measures as those at RAF Lakenheath.

The statement read: “We cannot say exactly how RAF Mildenhall will be affected. We can say, however, that there are no plans to relocate a set number of active duty service members from RAF Mildenhall back to the United States.

“Our base’s Airman & Family Readiness Center, along with many other base agencies, is working hard to ensure that any of our service members who are / will be affected by these force management programs receive as much assistance as possible, so they can more easily transition into the civilian workforce.”

While the sequestration programme will come into effect over five years, the bulk of job cuts will be made this year according to documents released by the air force.

Boards determining involuntary redundancies will meet between May and July.

Both bases have been features of the local area for more than 70 years, pumping millions of pounds into the local economy.

County councillor Colin Noble, who grew up in and represents Lakenheath, said: “When these things are announced it’s always a concern in the area, particularly because we very much welcome American personnel and so many people are employed in working on the bases and providing services to the air bases.

“But we also recognise the changing nature of their operational requirements. We understand and accept that change will always be a part of USAF Mildenhall and USAF Lakenheath.”

Senior air force staff held briefings at both Mildenhall and Lakenheath in December, just days after the overall details of sequestration were announced.

Bosses said they hoped to make the majority of cuts through voluntary arrangements, but those with poor disciplinary records would be among the most likely to go.